Degradation of poly(tetramethylene succinate) by thermophilic actinomycetes

Various thermophilic actinomycetes were screened for their ability to degrade a high melting point, aliphatic polyester, poly(tetramethylene succinate) (PTMS), at 50 °C. By using the clear zone method, Microbispora rosea, Excellospora japonica and E. viridilutea were found to have PTMS-degrading activity. In a liquid culture with 100 mg PTMS film, M. rosea subsp. aerata IFO 14046 degraded about 50 mg film sample after 8 days. Degradation at the amorphous regions of the PTMS film was observed by scanning electron microscopy. This strain was also able to completely degrade poly(-caprolactone).     

Novel nuclear and mitochondrial glycosylases revealed by disruption of the mouse Nth1 gene encoding an endonuclease III homolog for repair of thymine glycols

Endonuclease III, encoded by nth in Escherichia coli, removes thymine glycols (Tg), a toxic oxidative DNA lesion. To determine the biological significance of this repair in mammals, we established a mouse model with mutated mNth1, a homolog of nth, by gene targeting. The homozygous mNth1 mutant mice showed no detectable phenotypical abnormality. Embryonic cells with or without wild-type mNth1 showed no difference in sensitivity to menadione or hydrogen peroxide. Tg produced in the mutant mouse liver DNA by X-ray irradiation disappeared with time, though more slowly than in the wild-type mouse. In extracts from mutant mouse liver, we found, instead of mNTH1 activity, at least two novel DNA glycosylase activities against Tg. One activity is significantly higher in the mutant than in wild-type mouse in mitochondria, while the other is another nuclear glycosylase for Tg. These results underscore the importance of base excision repair of Tg both in the nuclei and mitochondria in mammals.     

Poly(L-lactide) degradation by Saccharothrix waywayandensis

Poly(l-lactide) (PLA) was degraded by more than 95 mg from 100 mg PLA film by an actinomycete, Saccharothrix waywayandensis, growing in 100 ml liquid culture containing 0.1% (w/v) gelatin. In addition to degrading PLA, this strain assimilated the major degradation product of PLA, l-lactic acid.     

Enzymatic synthesis of hydrophilic undecylenic acid sugar esters and their biodegradability

To enhance water solubility of 10-undecylenic acid, which has anti-fungus, anti-bacterial and anti-virus activity, d-glucose, trehalose and sucrose were regioselectively esterified with vinyl 10-undecylenic acid ester in dimethyl formamide by a commercial protease, Bioprase conc., from Bacillus subtilis. 6-O-(10-Undecylenoyl) d-glucose, 6-O-(10-undecylenoyl) trehalose and 1-O-(10-undecylenoyl) sucrose were obtained. The influence of structural variation by changing the sugar moiety was analyzed the surface tension and biodegradability.     

Phenotypic characterization of a human synovial sarcoma cell line, SW982, and its response to dexamethasone

SW982 cells are characterized by expression of inflammatory cytokine and matrix metalloproteinase (MMP) genes and by their response to dexamethasone at different cell densities. They express genes encoding interleukin (IL)-1 beta; IL-6; transforming growth factor-beta; intercellular adhesion molecule-1; cycloxygenase (COX)-2; and MMPs, including MMP-1, MMP-2, MMP-13, and MT1-MMP; tissue inhibitor of metalloproteinase-2; and a disintegrin and metalloproteinase with thrombospondin motifs-4. Expression of all the genes examined was induced with 2 ng/ml IL-1 beta at low cell density. The cells, however, failed to express tumor necrosis factor-alpha, COX-1, and MMP-9, regardless of the presence of IL-1 beta. Dexamethasone significantly reduced IL-1 beta, IL-6, COX-2, and MMP-1 expression at high cell density. The results suggest that SW982 cells are a useful tool for studying the expression of inflammatory cytokine or MMP genes.     

Enzymatic synthesis of trehalose esters having lipophilicity

To improve trehalose lipophilicity, trehalose was regioselectively esterified with vinyl fatty acid esters in dimethyl formamide by protease from Bacillus subtilis to give 6-O-lauroyltrehalose, 6-O-myristoyltrehalose, 6-O-palmitoyltrehalose, 6-O-stearoyltrehalose, 6-O-oleoyltrehalose and 6-O-linoleoyltrehalose. The influence of structural variation by changing fatty acid substitute was examined by measurement of the surface tension and biodegradability.     

Soybean β-Conglycinin Prevents Age-Related Hearing Impairment

Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG), one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months) were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV), which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress.     

CugP Is a Novel Ubiquitous Non-GalU-Type Bacterial UDP-Glucose Pyrophosphorylase Found in Cyanobacteria

UDP-glucose pyrophosphorylase synthesizes UDP-glucose from UTP and glucose 1-phosphate and exists in almost all species. Most bacteria possess a GalU-type UDP-glucose pyrophosphorylase, whereas many cyanobacteria species do not. In certain cyanobacteria, UDP-glucose is used as a substrate for synthesis of exopolysaccharide cellulose in spite of the absence of GalU-type UDP-glucose pyrophosphorylase. Therefore, there should be an uncharacterized UDP-glucose pyrophosphorylase in cyanobacteria. Here, we show that all cyanobacteria possess a non-GalU-type bacterial UDP-glucose pyrophosphorylase, i.e., CugP, a novel family in the nucleotide triphosphate transferase superfamily. The expressed recombinant Synechocystis sp. strain PCC 6803 CugP had pyrophosphorylase activity that was highly specific for UTP and glucose 1-phosphate. The fact that the CugP gene cannot be deleted completely in Synechocystis sp. PCC 6803 suggests its central role as the substrate supplier for galactolipid synthesis. Galactolipids are major constituents of the photosynthetic thylakoid membrane and important for photosynthetic activity. Based on phylogenetic analysis, this CugP-type UDP-glucose pyrophosphorylase may have recently been horizontally transferred to certain noncyanobacteria.